Numerical investigation of piloted turbulent reacting methane/air jet

In this paper, the scalar transport effects on the prediction of piloted turbulent reacting jets are presented. Two scalar submodels, the equal and nonequal scales, are used with the standard k-epsilon first-order turbulence closure model. Combustion is modeled using the flamelet tabulated chemistry with a presumed mixture fraction/strain rate probability density function. Diffusion flamelets are generated by using the RUN-1DL code. Two piloted methane/air turbulent jet diffusion flames, namely, flames B and L, are numerically studied. These flames are experimentally documented and feature two different behaviors toward extinction based on their pilot-to-jet velocity ratios. Obtained numerical results are compared to experimental data. A good performance of the nonequal scales model in the prediction of piloted turbulent diffusion flames structure is assigned.